21985853136 has 80 divisors (see below), whose sum is σ = 61707258816. Its totient is φ = 6704990208.

The previous prime is 21985853107. The next prime is 21985853159. The reversal of 21985853136 is 63135858912.

It is a happy number.

It is a super-2 number, since 2×21985853136² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85390 + ... + 226413.

Almost surely, 2^21985853136 is an apocalyptic number.

21985853136 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21985853136 is an abundant number, since it is smaller than the sum of its proper divisors (39721405680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21985853136 is a wasteful number, since it uses less digits than its factorization.

21985853136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311940 (or 311934 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 51.

The spelling of 21985853136 in words is "twenty-one billion, nine hundred eighty-five million, eight hundred fifty-three thousand, one hundred thirty-six".